The field of the invention is in the art of ion implanted, p-n junction, solid state devices.
The creation of p-n junction devices by the diffusion process in common semiconductor material is well established. The creation of p-n junction devices in the exotic semiconductor materials such as zine selenide by diffusion has not been generally successful due to a phenomenon known as vacancy compensation as pointed out by King et al. in U.S. Pat. No. 3,383,567. While King et al. do mention the creation of p-n junctions in ZnSe by phosphorous ion implantation they appear to be mainly concerned with the creation of junctions in a diamond body substrate. Kellett et al. in U.S. Pat. No. 3,341,754 disclose the process of producing precision resistors in silicon semiconductor material by phosphorus ion implantation. Weisberg et al. in U.S. Pat. No. 3,459,603 disclose the method of fabricating diffusion phosphorus doped ZnSe crystals, to provide electroluminescent devices. Other patents that may be of interest in connection with the background of this invention are: U.S. Pat. Nos. 3,549,434, patentee M. Aven; 3,496,429, patentee R. J. Robinson; and 3,705,059 patentee Z. K. Kun.
The desirability of creating semiconductor devices in widebandgap II-VI compounds, (group II and group VI of Mendelyeev's Periodic Table), has been well recognized due to their excellent potential for electronic and optoelectronic applications such as visible injection electroluminescent devices and integrated optical circuit elements. ZnSe has been a particularly intriguing material because it is a highly efficient phosphor with a direct bandgap of 2.67 eV at room temperature and has the highest covalent bonding of the II-VI compounds. Although low-resistivity n-type ZnSe can be produced easily by conventional methods, the corresponding p-type ZnSe cannot due to self-compensation effects. Recent advances in ion implantation technology have shown it to be an effective means of introducing type converting dopants.
Further information on devices of this invention may be found in the following published articles by the inventors. Page 1444, Journal of Applied Physics, Vol. 45, No. 3, March 1974, entitled "Injection Electroluminescence in Phosphorus-Ion-Implanted ZnSe p-n Junction Diodes", and at page 538, Vol. 62 in the Proceedings of the IEEE for April 1974 entitled, "Switching and Memory Effects in Phosphorus-Ion-Implanted ZnSe Devices."